| evolution of rattlesnakes (viperidae; crotalus) in the warm deserts of western north america shaped by neogene vicariance and quaternary climate change. | during pleistocene, the laurentide ice sheet rearranged and diversified biotic distributions in eastern north america, yet had minimal physical impact in western north america where lineage diversification is instead hypothesized to result from climatic changes. if pleistocene climatic fluctuations impacted desert species, the latter would reflect patterns of restricted gene flow concomitant with indications of demographic bottlenecks. accordingly, molecular evidence for refugia should be presen ... | 2006 | 16968275 |
| in vitro cytotoxicity of l-amino acid oxidase from the venom of crotalus mitchellii pyrrhus. | l-amino acid oxidase isolated from crotalus mitchellii pyrrhus (cmp-laao) exhibited cytotoxicity against lncap prostate adenocarcinoma cells. the viability of lncap cells decreased in a concentration- and time-dependent manner upon administration of cmp-laao. cmp-laao induced apoptosis as evidenced by annexinv/pi staining using flow cytometry. an increase in caspase-9 and caspase-3 activity were also observed. the damaging effect of laao appears to be due to its enzymatic activity, that produces ... | 2017 | 28943466 |
| limitations of climatic data for inferring species boundaries: insights from speckled rattlesnakes. | phenotypes, dna, and measures of ecological differences are widely used in species delimitation. although rarely defined in such studies, ecological divergence is almost always approximated using multivariate climatic data associated with sets of specimens (i.e., the "climatic niche"); the justification for this approach is that species-specific climatic envelopes act as surrogates for physiological tolerances. using identical statistical procedures, we evaluated the usefulness and validity of t ... | 2015 | 26107178 |
| endogenous hepadnaviruses, bornaviruses and circoviruses in snakes. | we report the discovery of endogenous viral elements (eves) from hepadnaviridae, bornaviridae and circoviridae in the speckled rattlesnake, crotalus mitchellii, the first viperid snake for which a draft whole genome sequence assembly is available. analysis of the draft assembly reveals genome fragments from the three virus families were inserted into the genome of this snake over the past 50 myr. cross-species pcr screening of orthologous loci and computational scanning of the python and king co ... | 2014 | 25080342 |
| body size evolution in insular speckled rattlesnakes (viperidae: crotalus mitchellii). | speckled rattlesnakes (crotalus mitchellii) inhabit multiple islands off the coast of baja california, mexico. two of the 14 known insular populations have been recognized as subspecies based primarily on body size divergence from putative mainland ancestral populations; however, a survey of body size variation from other islands occupied by these snakes has not been previously reported. we examined body size variation between island and mainland speckled rattlesnakes, and the relationship betwe ... | 2010 | 20209105 |
| an aqueous endpoint assay of snake venom phospholipase a2. | phospholipase a2 (pla2), an enzyme found in most snake venoms, catalyzes the hydrolysis of phospholipids in biological membranes, and some have presynaptic neurotoxic activity. a synthetic substrate, 4-nitro-3-(octanoyloxy)benzoic acid, was synthesized and purified on a silica gel column using a published method. this substrate was used to develop an endpoint assay which is rapid and requires a minimum of equipment. this aqueous assay system allowed enzyme activity to be examined without the use ... | 1996 | 8931255 |
| case reports of envenomation and venom composition differences between two arizona populations of the southwestern speckled rattlesnake, crotalus pyrrhus (cope, 1867). | envenomations by the southwestern speckled rattlesnake (crotalus pyrrhus) are fairly rare. previous descriptions in the literature do not include locality, an important factor in the clinical symptoms or syndromes of snakebites resulting from geographic variation in venom composition. here, we describe two cases of envenoming by c. pyrrhus from two arizona localities (tinajas altas mountains, yuma county, and phoenix mountains, maricopa county). both patients experienced swelling, but neither de ... | 2019 | 31585139 |